Technical Field
The present invention relates to, e.g., a sensor device for measuring a measurement subject, and a management system including a sensor device and a server device for managing the sensor device.
Background Art
In our surrounding environment, various kinds of sensors are installed, and measurement data with a sensor are collected and analyzed by a server device (or a main body device). Then, using this analysis result, devices and the like installed in the surrounding environment are controlled.
When one server device has many sensors to be managed, and the number of measurements and the number of data transmissions increase in the sensor, the server device has to accumulate and analyze a large amount of data, and the server device fails to process the data or reduces the processing performance.
When the sensor frequently measures and transmits data, the sensor naturally consumes more power. For example, when the sensor is operated on a battery, and the sensor frequently measures and transmits data, the lifetime of the battery is reduced, and it is necessary to frequently replace the battery. On the other hand, when the number of measurements is reduced, it may be impossible to appropriately control the devices and the like.
Accordingly, the power consumption is reduced by preventing useless measurement and transmission. For example, Patent Document 1 discloses the following technique. Two cycles T1 (long cycle) and T2 (short cycle) and two thresholds α1 and α2 (α1≧α2) are set as measurement cycles of the sensor. Then, when the current measurement cycle is T1, the measurement cycle is changed as follows. When the change rate α of the measurement data with the sensor is more than α1, the measurement cycle is changed to T2. When the current measurement cycle is T2, the measurement cycle is changed as follows. When the change rate α of the measurement data is less than α2, the measurement cycle is changed to T2. As described above, both of the immediacy and power consumption of the measurement are achieved.
Patent Document 2 discloses a technique, in which a measured value with a sensor and a target range value are compared, and when a predetermined change is found in a comparison result for a predetermined number of times continuously or for a predetermined continuous time (in an embodiment, in a case where the measured value is less than the target range value for three times continuously), the measurement cycle is changed or the operation of the device is stopped.